Abstract
The intracellular yeastlike symbiotes in L. striatellus are destroyed by heat treatment (at 35.degree. C for the 1st 3 days of the nymph). The heat treatment shows a deleterious effect on the adult molt; a number of the insects fail to emerge. The administration of cholesterol to the heat treated insects largely promoted the adult molt. .beta.-Sitosterol also had an effect on the recovery of the deleterious effect. The heat treated 5th-instar nymphs fairly molted by application of ecdysterone. The deleterious effects seems to come from the collapse of the yeastlike symbiotes through steroid metabolism of the insect. The yeast-like symbiotes appear to play an important role in supplying sufficient sterol for the development of L. striatellus.